1. Field of the Invention
This invention relates to a vehicle door made up of a door panel and a door sash and, more particularly, to a vehicle door structure having a reinforced door lock mounting section.
2. Description of the Prior Art
FIG. 1 is a side view showing a typical conventional vehicle door structure and FIG. 2 is an enlarged sectional view showing the location of the door lock incorporated in the vehicle door structure of FIG. 1. The conventional vehicle rear door structure comprises a door sash 2 welded to an inner panel 4 which constitutes a door panel together with an outer panel 6. A door lock 8 is located inside the inner panel 4 and secured thereto by means of bolts 10. In such a conventional vehicle door structure, however, the door lock mounting section has a relatively large vertical length. This renders it very difficult to lower the waist line L and impedes provision of a wide field of vision. Furthermore, any attempt to lower the waist line L will cause a corresponding reduction in area S1 for welding and thus in connecting strength between the door sash 2 and the inner panel 4. In addition, since the door lock 8 is attached only to the inner panel 4, some troubles would result from its insufficient panel strength.